Methanolic extract of Citrus japonica fruits accelerates wound healing in rats: an experimental animal study and LC-HRESIMS metabolomic analysis

Abstract

Citrus japonica (C. japonica), known as Kumquat, is small-size edible fruit native to South Asian regions and reported for its anti-inflammatory and antioxidant properties. This manuscript aimed to investigate LC-HRESIMS-based metabolomic profiling and wound healing properties of C. japonica fruit extract hydrogel formulation. The metabolic profiling of the fruit extract was investigated using LC-HRESIMS. The extract was formulated in hydrogel preparation and examined for in vivo wound healing activity. Twenty rats were divided into four different groups (n = 5); the negative control group did not undergo any wound creation; the positive control group was wounded and did not receive daily application of a topical formulation based on the wound area; the reference group consisted of wounded rats treated with MEBO® ointment applied to the wound area. The remaining group of rats were wounded and received topical preparations of C. japonica with variations in the size of the applicator head. The effects of C. japonica fruit extract were examined on all phases of wound healing via assessment of the expression levels of key markers such as TNF-α, VEGF, PDGF, and TIMP-2. Besides, morphological and histopathological studies were conducted. The findings reveal that treatment with C. japonica extract expedites wound healing, showing comparable effectiveness to standard treatments like MEBO®. Understanding these molecular markers provides valuable insights for designing precise treatments that enhance the wound healing process and minimize complications in clinical settings. The LC-HRESIMS revealed the characterization of 21 secondary metabolites belonging to methoxylated flavonoids, phenolic acids, anthocyanins, and coumarins. C. japonica gel exhibits significant efficacy in wound healing in vivo and warrants further investigation for potential clinical applications.